Hey, following up on a near-disaster a few weeks ago. I had changed the timing belt in a B18C1 GSR, but due to some incorrect reference info, I put in a B18C5 belt instead, which is a few cm longer.

The engine ran horribly at first, with lots of distributor lug rattle from the lack of tension. Finally realized with HA-net members' advice what the problem was. I threw in the quick fix of having an assistant pull up on the tensioner spring during the belt tensioning process. That took out enough slack to smooth out operation and the car has been a reliable daily driver since.

It bogs at part throttle, though: timing discrepancy. Looking at the index marks, when the cams are at TDC1, the crank mark is maybe 2 degrees counterclockwise from its own TDC1 mark. This is presumably due to slightly different tooth spacing on the B18C5 belt versus the B18C1 engine. I've played around and retensioned a few times, but it always ends up the same way.

My options seem to be to get adjustable cam gears, or just put in a new correct B18C1 belt. I think I'll get the new belt.

But I noticed when shopping for the belt that some manufacturers, like Greddy with their new extra-strong belts, have the same model number for the belt for the -C1 and -C5 engines. Huh? What's up with that? Presumably something is getting traded off in the fit department. Maybe these belts don't fit either engine perfectly.